Vehicle muffler and particle separator

ABSTRACT

Engine exhaust gases enter a series of chambers through succeeding partitions containing orifices of decreasing size but increasing numbers. A baffle is located in each chamber downstream of its inlet orifices to change the flow direction of the exhaust gases in such a manner that particulate matter carried by the exhaust gases drops to the bottom of the chamber. The bottom of each chamber contains a false floor having openings therein and the particulate matter drops through the openings into storage compartments.

United States Patent 1 1 3,559,760

[72! Inventor Jack S. Ninomiya [56] References Cited Rockwwd- Mich- UNITED STATES PATENTS l QJ J- g 3.092.206 6/1963 Moreau l8l/68 [221 3,154,174 10/1964 Haining l8l/56X [451 Paemed 3 170 280 2/1965 R 181 36 3 [73] Assignee Ford Motor Company 87834 6 I965 g Dearbom Mich ryson et a a corporation of Delaware Primary ExaminerRobert S. Ward, Jr.

Altomeys--.Iohn R. Faulkner and Glenn S. Arendsen 54 VElllCLE MUFFLER AND PARTICLE SEPARATOR I exhaust gases 3 chambers 9 Claims, 2 Drawing Figs.

through succeeding partitions containing orifices of decreasing size but increasing numbers. A baffle is located in each [52] US. Cl 181/36, chamber downstream of its inlet orifices to change the flow 181/53, 181/69. 181/56; 55/276 direction of the exhaust gases in such a manner that particu- [5 l Int. Cl F0ln 1/08, late matter carried by the exhaust gases drops to the bottom of FOln 3/02 the chamber. The bottom of each chamber contains a false [50] Field of Search 18 1/363, floor having openings therein and the particulate matter drops 68, 69, 56. 46. 36, 53; 55/276 through the openings into storage compartments.

\ I i 46 z E 42 4 44 J6 i i 1 1 t z //4/ I /////////////i ////////,V//////// r as 64 66 66 6G VEHICLE MUFFLER AND PARTICLE SEPARATOR SUMMARY OF THE INVENTION The exhaust gases of combustion engines contain certain amounts of particulate material that contribute in some undetermined degree to atmospheric pollution. Particles from certain present day automotive internal combustion engines can include lead, lead compounds, other metals and metallic compounds derived from lubricating oils, carbon and organic sludge. The particles vary in size from less than 0.0l micron to about l microns. Particle quantities vary widely with engine operations; preliminary tests indicate that the vast majority of particles are produced during vehicle accelerations. Automotive engineers estimate that typical vehicle engine produces about 60 pounds of such particles in its first 50,000 miles of operation.

This invention provides an exhaust muffler for a combustion engine that not only muffles the sound of the exhaust gases but also removes particles therefrom. The muffler is relatively inexpensive and provides satisfactory muffling and particle removal over a wide range of exhaust gas flow rates and particle contents without causing excessive engine back pressure. An elongated housing having an inlet for connection to the engine exhaust manifold and an outlet communicating with the atmosphere encloses the essential structure of the muffler. A plurality of partitions divide the interior of the housing into a series of successive chambers. Each partition has orifices therein to admit exhaust gas flow into the chamber. The partitions are arranged to conduct the exhaust gases sequentially through the series of chambers and the orifices in each partition become progressively smaller from the inlet chamber to the outlet chamber. A baffle is located in each chamber directly downstream from the orifices admitting exhaust gases into that chamber. The baffle deflects the exhaust gases in a manner such that the inertia of particles carried by the exhaust gases causes the particles to drop out of the gas stream and fall to the bottom of the housing.

Particle removal depends primarily on the velocity the particles achieve in passing through the orifices in the partitions. This velocity also depends on the amount of exhaust gas passing through the muffler, which in turn depends on engine operation. Successive partitions having progressively smaller orifices extending over a wide size range remove particles of various sizes from gas streams of various velocities.

Orifices having a size capable of removing the largest particles from minimum exhaust gas flow rates preferably are placed in a centrally located partition. Downstream partitions then contain smaller orifices to remove the smaller particles anticipated for the exhaust gas flow. Upstream partitions contain larger orifices that have reduced effect on particle separation at low gas flow rates but become increasingly effective with rising flow rates. The initial partition contains orifices designed to remove the largest particles from the maximum gas flow rate. As exhaust gas flow rate increases from its minimum, the larger particle sizes are removed in preceding chambers having larger orifices. Thus, a muffler capable of effective particle removal over all anticipated flow rates includes a plurality of partitions having orifice sizes that extend beyond the particle and flow rate ranges anticipated for any one engine speed.

The muffler preferably is positioned with its longitudinal dimension substantially horizontal and each partition extending laterally across the longitudinal dimension to divide the housing interior into a plurality of longitudinally spaced chambers. These chambers preferably vary in size to remove sound waves having differing frequencies; in a preferred construction, the chambers decrease progressively from the inlet end to the outlet end. The orifice openings are groupedapproximately at the vertical center of the partitions and the baffle in each chamber preferably extends vertically upward beyond the highest inlet opening into that chamber but stops short of the roof of that chamber.

A false floor having appropriate openings therein is located in the bottom of each chamber. Particles separated from the gas stream in each chamber fall onto the false floor and even tually drop through the openings therein into storage spaces located across the bottom of the muffler. This false floor prevents the particles from being retained in the exhaust gas stream by travel over rough roads.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of a typical muffler and particle separator of the invention having a plurality of succeeding narrower chambers separated by partitions containing orifices of succeedingly smaller sizes. FIG. 2 is a perspective view of a series of chambers showing the relationship of the inlet orifices to the baffles and the particle storage areas.

DETAILED DESCRIPTION Referring to the drawings, the muffler separator of this invention comprises a housing 10 made up of a substantially cylindrical member 12 having its ends closed by an inlet plate 14 and an outlet plate 16. An inlet opening 15 approximately in the center of inlet plate 14 communicates with an engine and an outlet opening 17 in the approximate center of outlet plate I6 communicates through appropriate piping with the atmosphere. Muffler 10 is positioned in a vehicle so its longitudinal axis 18 is substantially horizontal.

A plurality of partitions 20, 22, 24, 26 and 28 are located in the interior of housing 10 where the partitions divide the interior into a plurality of successively narrower chambers 30, 32, 34, 36, 38 and 40. Inlet opening 15 communicates directly with chamber 30 and outlet opening 17 communicates directly with chamber 40.

Partition 20 has one or more orifices 42 located approximately in its vertical center area that connect chamber 30 with chamber 32. In similar fashion, partition 22 has a plurality of orifices 44 located in its center area where the orifices connect chamber 32 to chamber 34. Orifices 44 are smaller in size than the orifices 42. Partitions 24 has a plurality of smaller orifices 46, partition 26 has a plurality of smaller orifices 48 and partition 28 has a plurality of still smaller orifices 50.

Positioned in each chamber directly behind the orifice inlets to that chamber is a baffle 52, 54, 56, 58, 60 and 62. The baffles extend upward in a substantially vertical plane from the floor of cylindrical member 12. Each baffle extends somewhat above the highest inlet orifice to its chamber and each baffle has a large open portion 63 at its top.

A false floor 64 extends through the lower portion of at least one chamber and preferably through all chambers of the muffler. Floor 64 is substantially parallel to the axis 18 and defines a plurality of storage areas 66 at the bottom of each of the chambers. The portion of floor 64 in each chamber contains a plurality of openings 68. Openings 68 preferably are large enough to pass the largest particles separated from the exhaust stream in that chamber. Wire screen of less than about mesh can be used as the false floor. The openings also can decrease in size from the inlet end to the outlet end if desired.

In operation, engine exhaust gases enter the first chamber 30 of the muffler through inlet opening 15. The exhaust gases pass through orifice 42 at a relatively low velocity to enter chamber 32. Baffle 52 deflects the gases upward through open portion 63. The gases then pass through orifices 44 into chamber 34, are deflected upward by baffle 54, pass through the opening 63 defined by baffle 54, pass through orifices 46 into chamber 36, and in this manner pass successively through each chamber to exit from opening 17.

Each succeeding set of orifices inparts a greater velocity to the exhaust gases. When velocity reaches a critical velocity at which the largest entrained particles carried by the exhaust gases are unable to follow the deflection cause by the baffle immediately downstream of those orifices, such particles separate from the gas stream, drop onto false floor 64, and eventually pass through openings 68 into the storage area.

Subsequent orifices increase the velocity still further. which separates smaller particles. The last set of orifices act with the associated baffle to separate the smallest practical particle sizes and a relatively particle-free exhaust gas flows out of outlet 17.

As increasing engine speed produces increasing exhaust gas flow, the critical velocity for each particle size is attained in earlier orifices. Particle separation thus advances with increasing engine speed toward the first chamber 30, which is designed to separate maximum particle sizes at maximum flow rates.

Particles separated in each chamber drop through the openings of the false floor into the storage areas. The openings prevent significant reentrainment of previously separated particles by inhibiting particle movement back into the separating chamber. A small lip 70 can be formed around the bottom of each opening to assist in inhibiting such return movement.

in addition to separating particles, the differing size or volume of each chamber reduces the intensity of sound waves of differing wave lengths. Dimensions and volumes of the chambers can be varied within relatively wide limits to produce most desirable sound reductions.

Thus this invention provides a sound muffling and particle separating device that opt. rtes effectively over a wide range of exhaust gas flow rates and particle sizes. The device operates without generating excessive back pressures, requires virtually no maintenance and is relatively inexpensive.

We claim:

1. An exhaust muffler for mufi'ling the sound and removing particles from the exhaust of a combustion engine comprising:

an elongated housing having an inlet for connection to said engine and an outlet communicating with the atmosphere;

a plurality of partitions dividing the interior of said housing into a plurality of chambers, each partition having openings therein to permit exhaust flow between the chambers on each side of the partition, said partition being arranged to conduct exhaust gases sequentially through said chambers, the openings in said partitions becoming progressively smaller from the inlet end to the outlet end, and

a baffle located in each chamber where said baffle deflects the exhaust stream entering that chamber via said openings to remove particles carried by said exhaust stream, each of said chambers removing particles of differing sizes.

2. The muffler of claim 1 in which the longitudinal dimension of the muffler is substantially horizontal and said partitions extend laterally across said longitudinal dimension to divide the housing interior into a plurality of longitudinally spaced chambers.

3. The muffler of claim 2 in which the openings are grouped approximately at the vertical center of said partitions and the baffle in each chamber extends vertically upward beyond the highest inlet opening into that chamber but short of the roof of the chamber.

4. The muffler of claim 3 comprising a false floor member extending across the bottom of at least one chamber to define a storage area, said false floor member having an opening connecting the storage area with the chamber, said opening being large enough to pass the largest particles separated from the exhaust stream in that chamber.

5. The muffler of claim 4 in which said false floor extends across the bottom of each chamber to define a storage area for each chamber, each storage area being separate from each adjacent storage area.

6. The muffler of claim 5 in which at least one chamber differs in volume from another chamber to reduce the level of differing sounds of the exhaust stream.

7. The muffler of claim 1 comprising a false floor member extending across the bottom of at least one chamber to define a storage area, said false floor member havingan openin connecting the storage area with the chamber, said opening ing large enough to pass the largest particles separated from the exhaust stream in that chamber.

8. The muffler of claim 7 in which said false floor extends across the bottom of each chamber to define a storage area for each chamber, each storage area being separate from each adjacent storage area.

9. The muffler of claim 1 in which at least one chamber dif fers in volume from another chamber to reduce the level of differing sounds of the exhaust stream. 

1. An exhaust muffler for muffling the sound and removing particles from the exhaust of a combustion engine comprising: an elongated housing having an inlet for connection to said engine and an outlet communicating with the atmosphere; a plurality of partitions dividing the interior of said housing into a plurality of chambers, each partition having openings therein to permit exhaust flow between the chambers on each side of the partition, said partition being arranged to conduct exhaust gases sequentially through said chambers, the openings in said partitions becoming progressively smaller from the inlet end to the outlet end, and a baffle located in each chamber where said baffle deflects the exhaust stream entering that chamber via said openings to remove particles carried by said exhaust stream, each of said chambers removing particles of differing sizes.
 2. The muffler of claim 1 in which the longitudinal dimension of the muffler is substantially horizontal and said partitions extend laterally across said longitudinal dimension to divide the housing interior into a pLurality of longitudinally spaced chambers.
 3. The muffler of claim 2 in which the openings are grouped approximately at the vertical center of said partitions and the baffle in each chamber extends vertically upward beyond the highest inlet opening into that chamber but short of the roof of the chamber.
 4. The muffler of claim 3 comprising a false floor member extending across the bottom of at least one chamber to define a storage area, said false floor member having an opening connecting the storage area with the chamber, said opening being large enough to pass the largest particles separated from the exhaust stream in that chamber.
 5. The muffler of claim 4 in which said false floor extends across the bottom of each chamber to define a storage area for each chamber, each storage area being separate from each adjacent storage area.
 6. The muffler of claim 5 in which at least one chamber differs in volume from another chamber to reduce the level of differing sounds of the exhaust stream.
 7. The muffler of claim 1 comprising a false floor member extending across the bottom of at least one chamber to define a storage area, said false floor member having an opening connecting the storage area with the chamber, said opening being large enough to pass the largest particles separated from the exhaust stream in that chamber.
 8. The muffler of claim 7 in which said false floor extends across the bottom of each chamber to define a storage area for each chamber, each storage area being separate from each adjacent storage area.
 9. The muffler of claim 1 in which at least one chamber differs in volume from another chamber to reduce the level of differing sounds of the exhaust stream. 